Circular knitting machine and method of knitting



June 30, 1936. P. A. BENTLEY ET AL 2,045,938

CIRCULAR KNITTING MACHINE AND METHOD OF KNITTING Filed April 22, 1933 4 Sheets-Sheet 1 June 1935- P. A. BENTLEY ET AL I 2,045,938

CIRCULAR KNITTING MACHINE AND METHOD OF KNITTING Filed April 22, 1935 4 Sheets-Sheet 2 June 30, 1936.

P. A. BENTLEY ET AL CIRCULAR KNITTING MACHINE AND METHOD OF KNITTING Filed April 22, 1953 4 Sheets-Sheet 5 June 1936- P. A. BENTLEY ETAL 2,045,938

CIRCULAR KNITTING MACHINE AND METHOD OF KNITTING Filed April 22, 1933 4 Sheets-Sheet 4 Patented June 30, 1 936 UNITED. STATES PATENT; OFFICE 7 a M 2,045,938 i cmcULAn KNITTING MACHINE AND METHOD OF KNITTING Percival Arthur Bentley, Frederick Edward Deans,

Charles Frederick Manger, and Carlyle Herbert Wainwright, Leicester, England, assignors to The Bentley Engineering Company Limited,

- Leicester, England 1 Application sprites, 1933, Serial No. 667,444

I In Great Britain April 27, 1932 5 Claims. 661) This invention is concerned with improvements in or relating to circular knitting machines, and is particularly although not exclusively applicable to the superposed cylinder type of machine which is exemplified in the specifications of British Letters Patent Nos. 15008/1900; 24290/1912; and 171,483,

In circular knitting machines, the work (hose,

half-hose etc.) is usually produced in string for- ID mation, that is to say, each article following the first article knitted is joined to the article immediately preceding it in the order of knitting, by a few idle knitted courses. To separate the articles of the string'flthese idle courses arecut by \hand, with the result that a somewhat ragged and rather unsightly finish is frequently given to the articles.

An object of the present invention is to provide a method of knitting by which the articles of the string can be separated from one another a with facility and without the production of the ragged finish 'justmention'ed. I

A feature of the invention is, in the knitting by machine of articles in string formation, a

method of rendering easily separable the individual articles of the string which consists in knitting into the work at the location where separation between the articles is to be effected, one or more courses of special thread of a character such that it may be withdrawn from the work,

thereby to separate the articles it connects, without binding unduly with the loops of the workthread with which it has been interlinked in the knitting operation.

The characteristic possessed by said special thread, namely, that it is readily withdrawable from the work, may be due to the fact that it is interlinked with but a few of the loops of the work thread, in which case the course of special 40 thread, or each course if there are several such courses, will be composed of separate lengths of such thread, each length, apart from a possible slight overlap with another length, being interlinked with a group of loops of work-thread dif- 4 ierent from the group of said loops that is engaged by another of said lengths. with this arrangement, when all the separate lengths are withdrawn from the work, the articles previously connected by the special threads will be sepa- 50 rated from one another.

Alternatively, buta, single length of special thread may be employed and the nature of the material of which it is'composedrelied upon for;

the ready withdrawal of the thread from the 65 work. For instance, thespecial thread ma be 'cialthread is preferably knitted into the work mentioned. The illustrative construction hereinarrangement is advantageous, as it not only composed of a hard cotton yarn knitted into the work in one, or slightly more than one, course of the knitting. A single thread is preferred for the reason that it utilizesbut one of the several yarn feeders with which knitting machines are usually provided, or needs the provision of butane extra 5 yarn feeder.

. In employing a special thread according to the invention in work provided with, a welt, the speimmediately preceding the knitting of the welt itself, as by this procedure the welt forms a fluishing end to the article after the special thread has been withdrawn to separate the article from its preceding companion in the string of articles; In cases where the work is being made on a rib-knitting machine where the welt is made on 1/1 rib fabric, the special thread of the present invention is preferably knitted into the work by one only of the two sets of needles, say the needies of the lower or plain cylinder in. a machine of the superpos d cylinder .type. The special thread is thus knitted into the ribbed fabric by every alternate needle only of the machine. After the-special thread has been knitted in, the 25 machine forms the welt in the usual manner.

'be pulled out, as these loops are slackened by I the withdrawal of the special thread. A convenient procedure in the separation of the articles is described hereinafter.

In all the several cases above-mentioned, the special thread may be different in colour from the work thread so as to render it readily distinguishable therefrom.

The invention comprlsesalso mechanism for feeding to and-knitting by certain of the needles of the machine, a special thread as hereinbefore after described provides for the application to a knitting machine, for the purpose of dealing with such a thread, of a stitch cam, thread feeder, and 1 thread cuttingand trapping device all additional to the corresponding devices with which the machine is provided and all located at different points in the needle circle from the locations occupied by said corresponding devices. Such an readily enables the special thread to be knitted (as is desirable in some cases) by .one only of the two sets of needles in a machine provided with two such sets, but also tends to avoid overcro din of parts at the feeding po t which fre- 55- quently is already occupied by as many feeders as it will comfortably acconmiodate.

A convenient construction of mechanism for providing the work with the special thread before-mentioned, which may be termed a draw thread, will now be described by way of example and by the aid of the accompanyingdrawings as applied to a knitting machine of the superposed cylinder type having co-axial revolving needle cylinders and stationary cam boxes.

In the accompanying drawings:-

Figures 1 and 1a are elevations of part of the machine showing mechanism constituting an ad.- ditional feed point which is provided for the draw-thread;

Figure 2 is a plan of parts shown in Figure 1;

Figure 3 is a plan of parts shown in Figure 1a;

Figure 4 is an elevation of parts shown in Figure 3, looking in the direction indicated by the arrow in Figure 3;

Figure 5 is a development of cams in the upper and lower cam boxes as seen from the inner side of said boxes; and

Figure 6 is a diagram of knitted fabric including a draw thread and is illustrative of a method according to the'invention of knitting the draw thread into the fabric and of cutting the draw thread and the work thread to permit ready separation of the knitted articles of the string.

In the drawings the upper and lower needle cylinders of the machine are indicated respectively at I6 and I2, see Figure 1. For the draw thread, the machine is provided withan additional feed point which comprises a stitch cam I4, a thread feeder I6, and a thread trapper and cutter device I8 which is similar to the corresponding device described in application Serial No. 468,168, filed July 15, 1930. The additional feed point is located at a different part of the needle circle from that at which is located the usual feed point for the yarn or yarns normally knitted into the work; see Figure 5 which shows the position which the draw thread stitch cam I4 occupies'in relation to the usual stitch cams 26 and 22 which are employed in the normal operation of the machine during rotary and reciprocatory knitting respectively. In the present construction, the draw thread is intended to be introduced into the work just prior to the formation of a Welt on 1/1 rib knitting and the draw thread is knitted by the needles of'the plain cylinder only. The stitch cam I4 for the draw thread is therefore located in the lower cam box, i. e. the cam box relating to the plain needle cylinder, and is shown as a'bolt cam which is movable at predetermined times, by mecha nism presently to be described, into and out of a position in which it actuates the needles of the plain cylinder.

In the present construction the needle-actuating cams in the upper and lower cam boxes are arranged for the knitting of the draw thread, for plain and rib knitting and for the formation of heel and toe pouches and a welt, and the welt may be knitted either by the needles of the plain cylinder or (as described in U. S. Letters Patent 1,910,457 granted May 23, 1933) by'the needles of 'the rib cylinder. In Figurev 5, the path which the butts of the plain needle sliders follow during plain knitting is indicated by the full line 24. When a draw thread is to be knitted, the stitch cam I4 is moved inwardly towards the needle cylinder causing the butts to follow the path indicated by the dotted line 26. When the welt is to be knitted by the needles of the rib cylinder, two cams 28 and 36 are withdrawn from the path of the butts so that the butts then follow the dot-and-dash line 32, the needles of the plain cylinder at this time merely holding their loops. The cam 36 is preferably a bolt cam. The cam 28 is arranged to swing about a vertical axis 34, is spring-pressed outwardly from Y the needle cylinder, and is moved inwardly into buttengaging position by an extension from the cam I4 which extension is on that part of the cam I4 that is on the outer side of the cam box.

The draw thread feeder I6 (Figures 1 and 2) is adjustably secured by the set-screw 36 in the upper end of a spindle 3B which is rotatable in a tubular portion of a vertical post 46 fixed adjustably in a boss 32 of a casting M. This casting has a split portion 46 encircling a reduced part 48 turned on a casting 56 which is carried on a fixed part 52 of the machine. The split portion 46 of the casting '44 is contracted to grip the reduced part 48 of the casting 56 by means of the screw 54 engaging lugs 56 on said split portion. The thread feeder I6 is moved into the feeding position shown in Figure 2 against the cured to the feeder spindle 38, which pin passes through a slot 62 in the post 46and engages a projection 64 on a cam follower 66 which is mounted in a guide block 68 on the casting 44. The end I6 of the slot 62forms a stop for the pin 66 so that the position of the feeder I6 when adjacent the trapper and cutter device I8 may be set by circumferential adjustment of the post 46, a set screw I2 serving to maintain the adjustment.

The draw thread stitch cam I4 is pressed outwardly of the cam box by a spring 14 which forces it against a second cam follower I6 in the guide block 66.

The trapper and cutter device I3 is operatively connected, by a lever I3 pivoted at-86 upon said device, to a cam follower 82 in the guide block 68, a spring 84 tending to maintain the lever in contact with the follower. For purposes of adjustment the lever does not engage the follower directly but engages a screw 86 threaded in the follower 82. The three cam followers 66, I6, and 82 bear respectively against three cams 86, 96, and 92. These cams are mounted on the upper end of a vertical shaft 94 and are gripped between washers 96 by nuts 98. The end of the shaft 94 where the cams 88, 96, 92 are located is made D-shaped in cross-section by having a flat formed on it and the washers96 have D-shaped holes to fit the shaft so that their rotation on the shaft is prevented. The cams 88, 96, 92 have round holes and may be adjusted circumferentially on the shaft 94 and locked in their desired position by the washers 96 andnuts 98. the lower end of the shaft 94 is a ratchet wheel I66 which is operated by a pawl I62, pivoted at I64 (Figure 3) on a lever I66,

action of a spring 58 by means of a pin 66 sea spring I66 (Figure 1a) tending to maintain the pawl I62 in engagement with the ratchet wheel.

The lever I66 is pivoted at I69 on a bracket H6 05 fixed on a shaft I26, journalled in bearings I22 on aoeaoss arrangedhponthe sbaft fl below the ratchet 'wheel a friction device comprising a spring ltd, friction plates I00, I60 and a nut "0 for adjusta fixed part of the machine frame. The lever II! is moved by connections between it and a cam I (Figure 4) on the control drum'i26 of the machineso that at predetermined times it moves the push rod IM into and out of the path of the cam H2. The idle track for the push rod lid is round the outside of the cam M2. The connections between the control drum are and the lever M0 comprise the cam N2, the push rod H0 will be pressed against the side of the cam Ii 2 and the spring I32 will be compressed until the end of the cam II? has passed the push rod IIO when the latter will spring into the track of the cam I I2. A spring I serves to return the push rod IIO to its idle track after the required number of turning movements has been given to the vertical shaft 90 by the mechanism just described. a

In order to ensure that the five movements of the vertical shaft 90, which make up the complete cycle of operations for one draw thread. shall take place, even though the control drum I20 may have been moved on so that the push rod I00 is 1 free to fall off the end of the cam I20, two notches I00 are formed in the ratchet wheel I00, flve teeth apart (1. e. diametrically opposite one another, as there are ten teeth in the wheel) and a tooth I38 at one end of a bell-crank lever I00 is adapted to engage'these notches while the other end I02 of said lever lies alongside a projection I00 on the lever I iii if the push rod I I0in that lever is in its idle track. The lever I00 is pivoted at I00 on the v bracket H0 and the tooth I00, for the purpose of adjustment may, as shown, be formed on a block I00 adjustably secured to the lever end by a screw I00. In the position just described the vertical shaft 00 cannot be rotated as the projection I00 prevents the lever I00 from being turned in a direction which would remove the tooth I30 from the notch I 30 with which it is engaged. Whenthe lever H8 is moved into the operative position by theaction, of the cam I20 on the controldrum I20, the first movement of the ratchet wheel I00 places the end I 02 of the lever I00 behind (i. e. as shown in Figure 3), the projection I00. The lever H8 ,is thereby held in its operative positidm'irrespctive of the position of the control drumI20 until the tooth I38 on the lever I00 falls into a notch I30 by the action of a. spring I52. The push rod 0 is. then sprung back to its idle "track by the action of the spring I30. A spring I50 (Figure 3) connected to the leger I00 and to a fixed part I- tends to keep the lever pressed against the push rod iii.

In order that the tension of the spring (Figure 2), that acts upon the lever is of the trapper and cutter device it, may readily be varied, one end of the spring engages a plate i W which is secured to the pivot pin 80 by a screw use while the other end of the spring engages the lever 18. By slacking back the screw m2 the plate W0 may be turned to adjust the tension of the spring at and then the adjustment maintained by tightening up the screw m2 again. A sar t. ange ment is adopted in connection with the springs ltd and W2. To prevent overthrow of the ratchet wheel its under action of the pawl I02 re is ing the degree of compression of the spring I00.

' In the operation of the mechanism the first movement of the vertical shaft c'ausesthe stitch-cam It to be moved by the cam 00 to a position where it will engage the long butts of the needle sliders but not the short butts (the long and short butts being those which are normally used in connection with the knitting-of heels and toes).

across the needles but is not 'yet .taken by the needles as at this time they are moving past the feeder at a constant level, i. e. without any vertical movement. As soon as the first needle whose slider has a long butt reaches the stitch cam I0, however, this needle descends and receives the draw-thread in its book. The following needles, whose sliders also have long butts, also receive the draw-thread. The second movement of the vertical shaft 00 now takes place and the bolt cam I0 is thereby moved farther in so as to engage the short as well as the long butts. At the same time the trapper and cutter device I0 is opened by the cam- 02 to release the end of the draw-thread. This is timed to take place as,soon as the first needle, whose slider has a long butt,

. has safely received the draw-thread. The needle cylinders. continue to revolve and the needles to knit the, draw-thread and the trapper and cutter device ifl'to remain open until the long butts are again passing .the stitch cam I0. A further movement of the vertical shaft 00 allows the stitch j cam I0 to spring out to a position where it conv This movement takes place while the, short butts are passing the stitch cam it. The

tinues to remain open. The next movement of the vertical shaft 90 causes the feeder IE to move to. the inoperative position (i. e. adjacent the device I8) as soon as the last needle with a slider having a long butt has knitted the draw-thread.

. The thread is taken by the last 'needle which knitted it and by the feeder i6'into thetrapper and cutter device I8 which then,-by reason of another movement of the vertical shaft 90, closes and cuts and holds the thread, and the stitch cam ,sI0 springs out'to the inoperative position. The'vertical shaft 90 now ceases its movements and the mechanism remains idle until another draw-thread is required.

The machine now starts to knit the welt by only to be pulled through one loop and a hole in the welt thereby formed. In order to avoid this occurrence, the first, needle to suspend t ting.

for the welt is about the third or fourthneedle after the last one which knitted the draw-thread. A few loops of 1/1 rib are thus formed between the end of the draw-thread and the beginning of the welt and these serve to lock the end of the yarn.

Figure 6 is a diagram showing a portion of fabric including a draw thread all knitted in accordance with a method of the present invention. In this diagram, which shows the structure of the fabric in the region near the end of the draw thread and the beginning of the welt as seen from the inner side of the fabric, the fabric is shown laid out flat and not in the condition it assumes when knitted, and the lengths of the loops are exaggerated for the sake of clearness. The loops in each course-are formed in succession in the direction indicated by the arrow.

Course 200 is 1/1 rib fabric knitted at the main feed point and the draw thread 202 is knitted at the additional feed point into the plain loops (i. e. the loops formed by the needles of the plain cylinder) of this course 2MB. When the needles which have knitted the draw thread 202 next reach the main feed point, l/1 rib knitting is again knitted and course 20% is formed in which the plain loops are drawnthrough the draw thread loops and the rib loops (i. e. the loops formed by the needlesof the rib cylinder) are drawn through the rib loops of course 200. This operation continues for the 'full length of the draw thread which is knitted into one courseand a half or thereaboiits. During this period the plain needles knit two "courses-one at each feed plains why the rib loops appear longer than the point-and the rib needles knit one course, this exrib fabric the rib loops of which are indicated at 208. This secures the beginning endof the welt, the first loop of which is shown at 2H]. In the operation of separating the articles of the string, the draw thread is cut at about the point 2 I2 and courses 200 and 204 are cut at about the same Wale, say at points 2 and 2l6 respectively. The draw thread 202 to the right of the cut at 2l2 is pulled out, and course 200 to the right of the cut at 2 and course 204 to the left of the cut at 2I6 are then pulled out, thus leaving the welt clear with a few 1/1 loops at the beginning of the welt.

We claim:-

1. A knitting machine comprising a stitch cam movable between a needle-actuating position and an idle position, a thread feeder movable between a thread feeding position and an idle position, a thread trapper and cutter device operable to trap and cut and to release thread fed from said thread feeder, mechanism for actuating said stitchcam, thread feeder, and trapper and cutter device in a series of steps, a pattern control device for starting said mechanism into operation, and means for ensuring that said mechanism having been thus started shall coma under control of said pattern control device, and

a locking device operated by the pawl and ratchet device for maintainingsaid element in connecting position until said series of steps is completed.

3. A knitting machine comprising a. stitch cam movable between a needle-actuating position and an idle position, a thread feeder movable between a thread feeding position and an idle position, a thread trapper and cutter device operable to trap and cut and to release thread fed from said thread feeder, and mechanism for actuating said stitch cam, thread feeder, and trapper and cutter device comprising a shaft, a series of cams mounted on said shaft and adjustable circumferentially thereon, a washer between each of said cams, interengaging surfaces on said shaft and washers preventing rotation of the washers on said shaft, and means for exerting and maintaining pressure on said cams and washers ina direction axially of the shaft to secure the cams in adjusted position on the shaft.

4. A method of rendering easily separable the individual articles of a series of articles knitted in string formation by a circular knitting machine having upper and lower needle cylinders and having separate yarn feeding positions spaced circumferentially of the needle cylinders,

which comprises forming the fabric by knitting a thread with the needles of both cylinders at one feeding position, and knitting a draw threa for at least a course at a second feeding position with the needles of one cylinder only, continuing the knitting of the fabric with all needles, and subsequently removing the draw thread to slacken certain of the loops of the fabric.

5. A method of rendering easily separable the individual articles of a series of articles knitted in string formation by a circular knitting machine having upper and lower needle cylinders and having separate yarn feeding positions spaced circumferentially of the needle cylinders, which comprises forming the fabric by knitting a thread with the needles of both cylinders at one feeding position, and introducing a draw thread at a second feeding position with the needles of one cylinder, the loops of the draw thread interlocking with the loops formed at said first feeding position by the same cylinder, whereby two courses are knitted by one cylinder and one course by the other cylinder simultaneously, and subsequently removing the draw thread to slacken certain of the loops of the fabric.

' PERCIVAL ARTHUR BENTLEY.

FREDERICK EDWARD DEANS. CHARLES FREDERICK MANGER. CARLYLE HERBERT WAINWRIGHT. 

